Modeling for Flexibility and Consistency: An Integration Capability for Mesoscopic DTA and Microscopic Traffic Simulation Models (TTI-2009-7)

The integration of mesoscopic and microscopic simulation models provides expanded dimensions of modeling capabilities for existing Dynamic Urban Systems for Transportation (DynusT) and VISSIM users to take advantage of the strengths of both models. A new integration tool was created with the use of a Python code to create a VISSIM model from a DynusT sub-area cut. The use of dynamic traffic assignment to generate links, nodes, vehicle paths, flows, and especially dynamic time-dependent routes tremendously improves transportation system operational planning analyses. The new integration tool alleviates the need to re-create the entire network from scratch again at the microscopic level. This offline conversion tool has advantages over real-time integration tools in that there is no need to create highly accurate microscopic models before the integration process. However, the conversion process is not without consistency issues. Microscopic models are designed to analyze traffic at a much higher level of fidelity than mesoscopic models. Mesoscopic models have different time resolutions, traffic dynamics, and link geometries. This report outlines the conversion process between DynusT, a mesoscopic simulation model, with a microscopic counterpart, VISSIM. In addition, the report addresses the many consistency issues that arose during the conversion process and attempts to alleviate many of these obstacles. A case study was also performed to analyze the outputs of both models for comparison. A comparison of output results was analyzed for consistency once the calibration process was completed.